A taxpayer had AGI of $300,000 in 2019 and AGI of $250,000 in 2018. When filing her 2019 return, she expects her unpaid tax liability to be at least $1,000. She must make estimated payments equal to the smaller of 90% of the tax shown on her 2019 return or

A. 110% of the tax on the 2018 return because 2018 AGI was greater than 2019 AGI.
B. 110% of the tax on her 2018 return because 2018 AGI was more than $150,000.
C. 100% of the tax on the 2019 return because 2019 AGI was more than $100,000.
D. 100% of the tax on her 2018 return regardless of 2019 AG